Ice and snow caused problems for drivers in South Otago at the weekend.
Constable Will Pentelow, of Milton, said black ice was the main cause of several crashes.
State Highway 1 between Balclutha and Milton was blocked for about two hours from about 9pm on Sunday when two vehicles travelling in opposite directions collided after one went out of control on black ice and drifted over the centre line.
There were two occupants in the southbound vehicle and one in the northbound vehicle, along with as a Jack Russell terrier.
There were no injuries in the crash. Traffic was diverted through Kaitangata.
Const Pentelow said three other crashes between Balclutha and Clinton were caused by black ice or snow.
One person was taken to hospital from one of the incidents.
"The other two were just minor with vehicles basically sliding off the road,'' he said.
The police reminded motorists to be aware of the winter conditions and adjust their driving accordingly.
Clutha District Council communications co-ordinator Rachel Askew said it was impossible for the council to grit every road in the district and roading contractor SouthRoads prioritised the worst affected high-risk areas and roads.
Possible problem streets in Balclutha would be assessed to see if any action was needed.
